Behave more like a caveman.

That’s the advice of a Kansas University professor who thinks he’s found a medication-free way to beat depression, a major illness that has afflicted about 20 percent of Americans.

And Steve Ilardi’s cure includes mimicking the habits of our hunting and gathering ancestors of 2 million years ago.

“The results have been very encouraging,” the KU psychology professor said about his regimen.

Ilardi has come up with a six-part regimen designed to reconnect depression sufferers with their hunter-gatherer roots – more exercise, more sunlight, more sleep, more fish oil, less isolation and fewer negative thoughts.

He calls his system Therapeutic Lifestyle Change or TLC.

Last semester, Ilardi assembled a group of five adults, all of whom had been diagnosed with severe depression. Some had suffered for at least a year, but all study participants had been depressed at least six months. The group met about once a week for 15 weeks.

Of the five participants, four “experienced a highly favorable treatment response,” Ilardi said, noting that the results beat the 50 to 60 percent response rate for anti-depressants.